Removing fluid from a structure can be challenging, particularly for large or complicated structures. For example, for an oil and gas well, drilling fluids may be introduced into the well during the drilling and completion process. This drilling fluid may deposit materials along the walls of the well, hindering production of hydrocarbons. As part of a cleanup process, before the production of hydrocarbons from the well begins, a team may introduce a treatment fluid to remove the deposits and recover the drilling fluid. Determining whether the drilling fluid has been removed from the well may not be simple, particularly with multi-lateral wells. An inefficient cleanup can cost a company time, money, and result in less recoverable reserves due to permanent damage to the formation.